User`s manual

Relay Multiplexer Command Reference 69
:SOURce
TRIGger:SOURce BUS|EXTernal|HOLD|IMMediate specifies the trigger source
to advance the channel list during scanning.
Parameters
Comments • Enabling the Trigger Source: The TRIGger:SOURce command only selects
the trigger source. The
INITiate[:IMMediate] command enables the trigger
source.
• Using the TRIG Command: You can use TRIGger[:IMMediate] to advance the
scan when
TRIGger:SOURce BUS or TRIGger:SOURce HOLD is selected.
• Using External Trigger Inputs: With TRIGger:SOURce EXTernal selected,
only one switchbox at a time can use the external trigger input at the
E1300/E1301 Mainframe "Event In" port. The trigger input is assigned to the
first switchbox requesting the external trigger source.
• Assigning External Trigger: A switchbox assigned with TRIG:SOUR EXT
remains assigned to that source until it receives a command to change the
source to
BUS, HOLD, or IMMediate. When the source is changed, the external
trigger source is available to another switchbox (with a
TRIGger:SOURce
EXTernal
command). Another switchbox cannot receive an external trigger
source if the source is already assigned, or an error is generated.
• Using Bus Triggers: To trigger the switchbox with TRIGger:SOURce BUS
selected, use the IEEE 488.2 common command
*TRG or the GPIB Group
Execute Trigger (
GET).
• "Trig Out" Port Shared by Switchboxes: See the OUTPut command.
• Related Commands: [ROUTe:]SCAN, TRIGger, ABORt
• *RST Condition: TRIGger:SOURce IMMediate
Example Scanning Using External Triggers
In the following example, the trigger input is applied to the E1300/E1301 Mainframe
"Event In" port.
TRIG:SOUR EXT
Sets trigger source to external.
SCAN (@100:115)
Sets channel list.
INIT
Starts scanning cycle.
trigger externally
Advances channel list to next channel.
Parameter Name Parameter Type Range of Values
BUS discrete *TRG command
EXTernal discrete Event In BNC port
HOLD discrete Hold triggering
IMMediate discrete Continuous triggering